Astrophysical S-factor of 14N(p,γ)15O

Formicola, A.; Imbriani, G.; Costantini, H.; Angulo, C.; Bemmerer, D.; Bonetti, R.; Broggini, C.; Corvisiero, P.; Cruz, J.; Descouvemont, Pierre; Fülöp, Zs.; Gervino, G.; Guglielmetti, A.; Gustavino, C.; Gyürky, Gy.; Jesus, A.P.; Junker, M.; Lemut, A.; Menegazzo, R.; Prati, P.; Roca, V.; Rolfs, C.; Romano, M.; Alvarez, C. Rossi; Schümann, F.; Somorjai, E.; Straniero, O.; Strieder, F.; Terrasi, F.; Trautvetter, H. P.; Vomiero, Alberto; Zavatarelli, S.

doi:10.1016/j.physletb.2004.03.092

Cited by 342 publications

(353 citation statements)

References 16 publications

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“…These facts suggest that 14 N/ 15 N increases with astration, whereas the gradient of 14 N/ 15 N with distance from the Galactic center within the disc suggests the opposite trend. We note that the recent factor-of-two reduction in the 14 N(p, γ) 15 O rate based on measurements at LUNA [119] and TUNL [120] [121] further increases the amount of 14 N in the dredged-up material and exacerbates the 14 N/ 15 N problem.…”

Section: Carbon and Nitrogenmentioning

confidence: 89%

Short-lived nuclei in the early Solar System: Possible AGB sources

et al. 2006

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The abundances of short-lived radionuclides in the early solar system (ESS) are reviewed, as well as the methodology used in determining them. These results are compared with the inventory estimated for a uniform galactic production model. It is shown that, to within a factor of two, the observed abundances of 238 U, 235 U, 232 Th, 244 Pu, 182 Hf, 146 Sm, and 53 Mn are roughly compatible with long-term galactic nucleosynthesis. 129 I is an exception, with an ESS inventory much lower than expected from uniform production. The isotopes 107 Pd, 60 Fe, 41 Ca, 36 Cl, 26 Al, and 10 Be require late addition to the protosolar nebula. 10 Be is the product of energetic particle irradiation of the solar system as most probably is 36 Cl. Both of these nuclei appear to be present when 26 Al is absent. A late injection by a supernova (SN) cannot be responsible for most of the short-lived nuclei without excessively producing 53 Mn; it can however be the source of 53 Mn itself and possibly of 60 Fe. If a late SN injection is responsible for these two nuclei, then there remains the problem of the origin of 107 Pd and several other isotopes. Emphasis is given to an AGB star as a source of many of the nuclei, including 60 Fe; this possibility is explored with a new generation of stellar models. It is shown that if the dilution factor (i.e. the ratio of the contaminating mass to the solar parental cloud mass) is f 0 ∼ 4×10 −3 , a reasonable representation for many nuclei is obtained; this requires that ( 60 Fe/ 56 Fe) ESS ∼ 10 −7 to 2×10 −6 . The nuclei produced by an AGB source do not include 53 Mn, 10 Be or 36 Cl if it is very abundant. The role of irradiation is discussed with regard to 26 Al, 36 Cl and 41 Ca, and the estimates of bulk solar abundances of these isotopes are commented on. The conflict between various scenarios is emphasized as well as the current absence of an astrophysically plausible global interpretation for all the existing data. Examination of abundances for the actinides indicates that a quiescent interval of ∼ 10 8 years is required for actinide group production. This is needed in order to explain the data on 244 Pu and the new bounds on 247 Cm. Because this quiescent interval is not compatible with the 182 Hf data, a separate type of r-process event is needed for at least the actinides, distinct from the two types that have previously been identified. The apparent coincidence of the 129 I and trans-actinide time scales suggests that the last heavy r contribution was from an r-process that produced very heavy nuclei but without fission recycling so that the yields at Ba and below (including I) were governed by fission.

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Section: Carbon and Nitrogenmentioning

confidence: 89%

Short-lived nuclei in the early Solar System: Possible AGB sources

et al. 2006

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“…Note that revisions to energetically important reaction rates can have a significant impact on stellar ages. Revisions of the 14 N(p, γ) 15 O rate by Formicola et al (2004) led to an increase in the predicted age of the oldest globular clusters , in addition to altering the lifetimes and luminosities of advanced evolutionary phases of low-mass stars (Pietrinferni et al 2010). When utilising a given set of tracks, one should always check that the reaction rates used are up-to-date.…”

Section: Discussionmentioning

confidence: 99%

Confronting uncertainties in stellar physics

Stancliffe

Fossati

Passy

et al. 2016

A&A

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We assess the systematic uncertainties in stellar evolutionary calculations for low-to intermediate-mass, main-sequence stars. We compare published stellar tracks from several different evolution codes with our own tracks computed using the stellar codes stars and mesa. In particular, we focus on tracks of 1 and 3 M at solar metallicity. We find that the spread in the available 1 M tracks (computed before the recent solar composition revision) can be covered by tracks between 0.97−1.01 M computed with the stars code. We assess some possible causes of the origin of this uncertainty, including how the choice of input physics and the solar constraints used to perform the solar calibration affect the tracks. We find that for a 1 M track, uncertainties of around 10% in the initial hydrogen abundance and initial metallicity produce around a 2% error in mass. For the 3 M tracks, there is very little difference between the tracks from the various different stellar codes. The main difference comes in the extent of the main sequence, which we believe results from the different choices of the implementation of convective overshooting in the core. Uncertainties in the initial abundances lead to a 1−2% error in the mass determination. These uncertainties cover only part of the total error budget, which should also include uncertainties in the input physics (e.g., reaction rates, opacities, convective models) and any missing physics (e.g., radiative levitation, rotation, magnetic fields). Uncertainties in stellar surface properties such as luminosity and effective temperature will further reduce the accuracy of any potential mass determinations.

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“…6) Nuclear Astrophysics Compilation of REaction rates (Angulo et al 1999). 7) Laboratory Underground Nuclear Astrophysics (Formicola et al 2004). OP: Badnell et al (2005), Seaton (2005); Wichita: Ferguson et al (2005); OPAL96: Iglesias & Rogers (1996).…”

Section: Stellar Model Comparisonsmentioning

confidence: 99%

A seismic and gravitationally bound double star observed byKepler

Appourchaux

Antia

Ball

et al. 2015

A&A

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Context. Solar-like oscillations have been observed by Kepler and CoRoT in many solar-type stars, thereby providing a way to probe stars using asteroseismology. Aims. The derivation of stellar parameters has usually been done with single stars. The aim of the paper is to derive the stellar parameters of a double-star system (HIP 93511), for which an interferometric orbit has been observed along with asteroseismic measurements. Methods. We used a time series of nearly two years of data for the double star to detect the two oscillation-mode envelopes that appear in the power spectrum. Using a new scaling relation based on luminosity, we derived the radius and mass of each star. We derived the age of each star using two proxies: one based upon the large frequency separation and a new one based upon the small frequency separation. Using stellar modelling, the mode frequencies allowed us to derive the radius, the mass, and the age of each component. In addition, speckle interferometry performed since 2006 has enabled us to recover the orbit of the system and the total mass of the system. Results. From the determination of the orbit, the total mass of the system is 2.34 +0.45 −0.33 M . The total seismic mass using scaling relations is 2.47 ± 0.07 M . The seismic age derived using the new proxy based upon the small frequency separation is 3.5 ± 0.3 Gyr. Based on stellar modelling, the mean common age of the system is 2.7-3.9 Gyr. The mean total seismic mass of the system is 2.34-2.53 M consistent with what we determined independently with the orbit. The stellar models provide the mean radius, mass, and age of the stars as R A = 1.82−1.87 R , M A = 1.25−1.39 M , Age A = 2.6-3.5 Gyr; R B = 1.22−1.25 R , M B = 1.08−1.14 M , Age B = 3.35-4.21 Gyr. The models provide two sets of values for Star A: [1.25-1.27] M and [1.34-1.39] M . We detect a convective core in Star A, while Star B does not have any. For the metallicity of the binary system of Z ≈ 0.02, we set the limit between stars having a convective core in the range [1.14-1.25] M .

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Astrophysical S-factor of 14N(p,γ)15O

Cited by 342 publications

References 16 publications

Short-lived nuclei in the early Solar System: Possible AGB sources

Short-lived nuclei in the early Solar System: Possible AGB sources

Confronting uncertainties in stellar physics

A seismic and gravitationally bound double star observed byKepler

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